// Point to the graph layer, assuming here it already exists
range rGly = [Graph1]1!;
// Loop over all sheets in all books
doc -e LB {
   // Check to see if workbook, so can leave out matrix books
   if(2 == exist(%h,2))
   {
     // Declare range using column name of c100
     range ry=col(c100);
     // Use plotxy X-function to add plot to specified layer
     plotxy iy:=ry plot:=200 ogl:=rGly;
   }
}
// Can use legend update XF so legend shows data range for example;
win -a Graph1;
legendupdate mode:=dr;